A common issue that can occur when installing a WordPress themes is “The package could not be installed. The theme is missing the style.css stylesheet.” error message being displayed when uploading or activating the theme. One of the reasons you may receive this error is if you have uploaded the incorrect file. You have 2 options for downloading your theme.
The Installable WordPress file can be used for the installation process, while the other one does contain additional files such as documentation files, slider examples etc. Which means you need to unzip this package first and then use the inner “brooklyn.zip” for the installation.